Transcript Nuclear Power – the issues

Nuclear Power – Why now?
Martin Sevior, School of Physics, University of Melbourne
http://nuclearinfo.net
http://nuclearinfo.net
Ivona Okuniewicz
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Alaster Meehan
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Gareth Jones
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Damien George
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Adrian Flitney
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Greg Filewood
Technical Support
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Lyle Winton
Reviewed by:
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Dr. Andrew Martin
Web Design
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University of Melbourne Writing Center
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http://nuclearinfo.net
Energy and Entropy
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2nd Law of Thermodynamics
Entropy tends to increase
Sharing of energy amongst all possible
states
Life is in a very low state of entropy
To exist it must create large amounts of
entropy elsewhere. (S = Q/T)
Life requires large amounts of Energy.
http://nuclearinfo.net
Life and energy
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Life takes energy from the sun
Life represents a
~0.02%
decrease in
entropy from the
sun heating earth
http://nuclearinfo.net
Energy and civilization
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Our Civilization is based on cheap energy and
machines
Previous civilizations utilized humans and
animals. (Still the case for large parts of the
world.)
Given sufficient quantities of energy our
civilization can generate all the products it needs.
(Food, Health, Metals, Plastics, Water)
http://nuclearinfo.net
Energy in Australia
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Australia’s Electricity needs are currently
supplied by 40 GigaWatts of power
stations.
Our electricity demand is forecast to grow
by over 2% per year to 2020
On average 1.0 GigaWatts increase each
year
Equivalent to Loy-Yang B Power Station
http://nuclearinfo.net
Energy in the World
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China (pop 1.4 Billion) growing at 10% per year.
India (pop 1 Billion) growing at 6% per year.
Both aspire to Western standards of living
China likely to achieve current Australian
standard in 2040’s
Effect will be to triple world energy consumption.
Only a large scale trade embargo will prevent
them from effectively competing with the west.
http://nuclearinfo.net
World Energy Growth.
Energy Growth by “region”
Energy Growth by
source
Projections are “business as usual”
Source: U.S. Energy Information Administration.
http://nuclearinfo.net
How long can we keep using Oil?
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The rate of Oil usage is substantially
greater than the rate of new Oil discoveries
Developing Nations have become
competitors for Oil
Simple extrapolation
shows Oil exhausted
by 2036
http://nuclearinfo.net
Is Oil coming up against a wall?
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Australia’s Oil production peaked in 2000
Will/When will World Oil production peak?
(http://sydneypeakoil.com/phpBB/viewtopic.php?t=1972)
http://nuclearinfo.net
Global Climate Change
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The Earth’s atmosphere acts as a
“Greenhouse”. Traps heat that would
otherwise be radiated to space.
Carbon Dioxide (CO2) is the 2nd largest
contributor (and biggest driver)
Carbon Dioxide is also the fundamental
byproduct of Fossil Fuel consumption
Large scale use of Fossil Fuels has
substantially increased CO2 concentration
http://nuclearinfo.net
CO2 increase in the Atmosphere
http://nuclearinfo.net
Global Climate Change
Past world temperature changes
The current CO2 concentration is
unprecedented over half a million
years
Predicted world temperature changes
The different curves are different
predictions based on different
physical assumptions and future
CO2 emissions
http://nuclearinfo.net
Global Temperature Measurements
http://nuclearinfo.net
Myths about Climate Change
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Myth- Water vapour is the main source of
Greenhouse heating so CO2 makes no difference.
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Myth - CO2 absorption lines are saturated.
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Residency time of water is 10 days, CO2 is ~100
years. CO2 is the driver, water vapour provides
feedback/amplification.
Only true at ground level. The upper atmosphere is
sensitive to CO2 concentration
Net effect of doubling CO2 is an additional 4
watts/m2 extra heat.
No climate model shows a decrease in
temperature with an increase in CO2
http://nuclearinfo.net
Predictions for CO2 outputs
The developing world will likely produce more CO2
emissions than the West before 2020
Only a large scale trade embargo on China and India and the
rest of the developing world will prevent competition and
growth
http://nuclearinfo.net
Greenhouse Emission targets
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Kyoto protocol
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Future
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Reduce Greenhouse emissions by 5.2% from 1990
levels by 2008-2012
This is extremely hard. eg Canada has increased it’s
emissions by 20% since 1990
Reduce greenhouse emissions by 60% from 1990
levels by 2050 to stabilize temperature rise to 2 C
Can we get away with “cheating”?
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What if USA adopts Kyoto?
http://nuclearinfo.net
Australian CO2 emissions
Around 50% of Australia’s CO2 emissions are from
electricity production.
http://nuclearinfo.net
Total World CO2 emissions
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Total world demand for energy is expected
to at least double by 2050
Much is this growth is in the third world
which needs energy to escape poverty
The default solution to supply this energy
is to burn more fossil fuels
Achieving world 60% reduction in CO2
emissions will be impossible if this
happens
http://nuclearinfo.net
The transition.
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Having access to large amounts of cheap energy
is vital for our civilization.
Over the next human generation we will need to
manage a transition from our Fossil-Fuel based
energy sources
The combination of resource depletion and
Climate Change mitigation forces this.
Getting this right is vital for the world we leave
our children.
I believe that this is one of the great issues facing
this generation.
http://nuclearinfo.net
Nuclear Energy
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About 6 Billion years ago a supernova exploded
in this region of space.
About 1 solar mass of hydrogen was converted to
Helium in about 1 second
All the elements heavier than Lithium were
created making life possible in the solar system
A tiny fraction of the energy was used to create
heavy elements like Uranium and Thorium.
http://nuclearinfo.net
Nuclear Energy
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Chemical reactions release a few electronvolts of energy per reaction.
Nuclear Fission releases 200 Million electron volts per reaction
A neutron is captured by 233U,235U or
239Pu. The nucleus breaks apart and
releases 2-3 more neutrons. These in
turn can induce further fissions.
http://nuclearinfo.net
Nuclear energy
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The energy release from a single fission
reaction is about one-tenth that of an antimatter annihilation.
There is as much energy in one gram of
Uranium as 3 tonnes of coal.
The reaction produces no CO2
So how much Uranium is present on Earth?
http://nuclearinfo.net
Uranium Abundance.
The Earth’s crust is estimated to contain 40 trillion
tonnes of Uranium and 3 times as much Thorium.
 We have mined less than a ten millionth of this.
(We have extracted about half of all conventional Oil)
 If burnt in a “4th Generation” reactor provides 6
Billion years of energy.
 If burned in a current reactor enough for 24
Million years.
 But most is inaccessible. How much is really
available?
 Look at Energy cost of mining compared to energy
Generated in Reactors
http://nuclearinfo.net
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Uranium Abundance
Proven reserves as of June 2006 amount to 4.7 Million tonnes,
sufficient for 85 years at present consumption rates
Rossing mine in Namibia has a Uranium
abundance of 350 ppm and provides an
energy gain of 500
Extrapolating to 10 ppm provides an
energy gain of 14
4th Generation reactor (50 times more
efficient Uranium usage) provides an
energy gain of 100 at 2 ppm
At least 8,000 times more Uranium can be usefully mined using
current reactors. 32,000 times more with 4th Generation. (96
million years worth.)
http://nuclearinfo.net
Uranium in Sea Water
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Very low concentration 3 mg/m^3, but a huge
resource ~ 4.5x109 tonnes
Japanese experiment recovered > 1 Kg in 240 day
exposure
http://nuclearinfo.net
Nuclear Power
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Nuclear Power has been demonstrated to work at large scale.
France (80% Nuke, 20% Hydro) and Sweden (50% Nuke, 50%
Hydro) have the lowest per capita greenhouse emissions of large
countries in the OECD
Australia, with it’s reliance on Coal-powered electricity, has the
highest
http://nuclearinfo.net
Nuclear Greenhouse Gas emissions
The Nuclear Fuel cycle is complex. How
much Greenhouse Gases are produced?
http://nuclearinfo.net
Vattenfall
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The Swedish Energy utility operates
Nuclear, Hydro, Wind, BioMass, Solar and
Fossil Fuel facilities.
Vattenfall have performed LifeCycle
Analyses for these.
These are described in Environment
Product Descriptions “EPD”.
Useful “Worlds Best Practice” reference
http://nuclearinfo.net
CO2 emissions from Nuclear
Vattenfall EPD calculations, Gas 400 gm/kw-hr,
Coal 700 – 1000 gm/kw-hr
http://nuclearinfo.net
Vattenfall CO2 emissions from other sources
http://nuclearinfo.net
CO2 Emissions from Wind Power
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Need ~6,000 2 MW Wind Turbines to match 1
Nuclear Plant (60 year lifetime)
Requires 8-14 times as much steel and concrete
http://nuclearinfo.net
Storm and Smith Theory
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They conclude that Uranium cannot be mined at Ore
concentrations below 0.01% U by mass
This implies energy cost at 0.01% of mining = energy gain of
reactor
Rossing Mine in Nambia. Ore 0.035%. 3000 tonnes mined
per year. Enough for 15 GW-Years.
Storm and Smith predict energy cost = 60 PJ
Measured energy cost of Rossing = 1 PJ
Namibia uses 55 PJ per year (2003)
Cost of 60 PJ ~ $1.7 Billion (diesel)
Value of Uranium at $100/kg = $300 Million
Similar for Olympic Dam, Ranger and all operating low
Grade mines
Storm and Smith are WRONG.
http://nuclearinfo.net
Nuclear Reactors
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Nuclear reactors work by purposely allowing a controlled chain
reaction.
This is controlled by adjusting the neutron multiplication factor.
Current nuclear technology mostly employs “Light Water Reactors”
which burn Uranium enriched in 235U from it’s natural 0.7% to around
3%
The reactor is shutdown and fuel is changed after the 235U abundance
has fallen to around 1.2%
This typically occurs every 2 years.
So every 2 years 60 tonnes of fuel is replaced
Compare to Coal fired plants which burn 3000 tonnes of fuel every
day.
http://nuclearinfo.net
Science of Nuclear Power
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Cross sections for fission
http://nuclearinfo.net
Thermal Nuclear Reactors
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Neutron cycle in 235U and 238U mixture
Self-sustaining
chain reaction.
Requires neutron
multiplication factor
k =1.00000
http://nuclearinfo.net
Control of Thermal Reactors
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Controlled via absorption in 238U
At least 20 times
more 238U than
235U
At higher temps
•Doppler broaden
•Harder spectrum
Increases 238U
absorption
http://nuclearinfo.net
Control of light water reactors
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Delayed neutron emission
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Negative temperature coefficient
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(k reduces with T)
Negative “void” coefficient.
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0.7% neutrons emitted after beta decay (8 seconds)
Loss of coolant through bubble formation or other
means, means no further moderation and a decrease
in reactivity.
“Massive loss of coolant”
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Decay heat problem
Second generation reactors have multiple active
backup and containment.
http://nuclearinfo.net
Radiation
Nuclear Energy produces vast amounts of
radioactivity which is extremely dangerous.
Effects of Radiation:
 Cell Death or Apoptosis
 Cancer Induction (0.06/Sv)
 Genetic Damage to Future Generations
(0.02/Sv)
However we are all exposed to radiation every
day of lives. It cannot be avoided.
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http://nuclearinfo.net
Radiation Exposure
Typical background exposure is 3000 micro-seiverts per year
http://nuclearinfo.net
Nuclear Safety
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Typical large Nuclear Power Plant contains
10 billion Giga-Becquerel's of activity.
1 Giga-Becquerel typically leads to an
unwanted exposure.
Nuclear Power Plants contain vast amounts
of dangerous material.
Safely handling this is a significant
challenge.
http://nuclearinfo.net
Safety – Reactivity Control
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Nuclear reactors work by keeping the neutron
multiplication factor to be 1
Multiplication factor is adjusted by changing the
configuration of neutron absorbers.
This possible because 0.6% of neutron emission
is delayed by a few seconds
Light water reactors naturally slow down when
the temperature increases – “negative temperature
coefficient”
Light water reactors naturally slow down if there
is a loss of coolant – “negative void coefficient”
http://nuclearinfo.net
Safety – Reactivity Control
Accidents:
Numerous things can (and do) go wrong during
operations.
These are normally handled through routine
adjustments of the reactor parameters
Worst case is massive loss of primary coolant.
Current reactor handle this with multiple redundant
systems to pump water through the core. “Active
Safety systems”
Next generation reactors employ Passive features
which rely on Laws of Physics to ensure safe
shutdown.
http://nuclearinfo.net
Safety
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The U.S. Nuclear Regulatory Commission (NRC)
requires reactors to be design so that “Core
damage accidents” occur less than 1 in 10,000
years of reactor operation.
In this case the radiation is contained within a
safety shell. (50 cm reinforced steel surrounded
by 1.3 meters of concrete.)
Current Reactors are estimated to have core
failure rates of 1 in 100,000 years of operation.
New reactors under investigation for deployment
are estimated to have failure rates of 1 in 2
million years of operation.
http://nuclearinfo.net
Safety
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The western nuclear power industry has the best
safety record of any large scale industrial activity.
Within the US, communities living close Nuclear
Power plants are overwhelmingly in favour of
continued operation.
There is strong competition between communities
to be the location of New Reactors.
As of February 2006, the NRC had received
“expressions of interest” for 17 new Nuclear
Power Plants in the USA. All have local support.
http://nuclearinfo.net
Safety - Chernobyl
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The Chernobyl reactor had a number terrible
deficiencies compared to Western reactors.
No containment structure
“Positive void coefficient” at low power.
“Control rods” were graphite tipped!
As part of an experiment, operators switched off
the safety interlocks
Reduced the Power of reactor to low level.
Strenuously tried to increase the power in an
unconventional operating environment.
Fundamental Failure of “Safety Culture”.
http://nuclearinfo.net
Nuclear Power Costs
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Total cost = Cost of Capital + Operating Costs
Operating costs of current plants are the lowest of
all forms except Hydro (typically 1.5 cents/KwHr).
New Nuclear plants are projected to cost less than
1.5 US Billion dollars and operate for 60 years.
BUT best new plants have First of their Kind risks
Projected Electricity costs are 2.2-3.8 US cents/KWHr (but up to 6 US cents/KW-Hr)
Current Australian Eastern Australian coal
electricity costs around 2.2 - 4 US cents/KW-Hr
“Clean Coal” expected to add 2 cents/Kw-Hr
http://nuclearinfo.net
Previous generation Nuclear Power
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In the USA Nuclear Power plants turned
out to be FAR more expensive.
Plant cost was 3 – 5 Billion for 1 GW
Operational availability was around 60%
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Design deficiencies – NRC mandated
changes
Two stage licensing
Fragmented industry for construction
Fragmented industry during operation
http://nuclearinfo.net
Current US experience
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Availability has increased to more than 90%
Specialist companies now operate the US fleet.
Costs average 1.6 cents/KW-Hr
Nuclear
Industry
expects new plants
cost 1.0 – 2.0
Billion per GW
2.3- 5 US
cents/KW -Hr
http://nuclearinfo.net
Nuclear Waste
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Nuclear Power plants produce 30 tonnes of
high level waste/year.
95% of the energy in the fuel remains
Waste consists of short-lived light fission
products and long-lived trans-Uranics.
Current waste handling procedure is to
leave spent fuel in cooling ponds for 20
years. Followed by either dry storage,
reprocessing or long term geologic disposal
http://nuclearinfo.net
Geologic Disposal
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3 mature proposals, Sweden, Finland and
USA.
Unprocessed waste requires isolation for
100,000 years
The Nordic proposal consists of a multiple
barrier burial deep in wet Granite Rocks
The US proposal consists of dry burial
underground with easy retrieval.
http://nuclearinfo.net
Finish proposal
Spent Fuel is placed in Cast Iron Insert. Then in copper canister
Canister is embedded in Bentonite clay
Then buried in Granite rock 500 meters underground
http://nuclearinfo.net
Multiple Barriers
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The fuel itself retains the fission products.
Cast iron insert
Studied of Copper in anaerobic environment show
stability over 100,000 years
Bentonite Clays swell on wetting removing oxygen.
Also retain fission products.
Granite and infill isolate waste from the environment.
Granites show affinity for trans-Uranics
Oklo “natural” reactor show fission products have not
moved over 1.8 Billion years.
Strong scientific case that nuclear can be isolated
http://nuclearinfo.net
Nuclear Waste
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There is a strong Scientific case that Nuclear
waste can be safely sequestered.
However it is expensive and takes a long time to
plan.
The USA’s Yucca mountain repository is
insufficient for even the current generation.
Factor of 5 – 10 expansion of the nuclear industry
would be helped with an improved waste
management system.
UREX reprocessing and “fast-neutron” Burner
Reactors – 2006 GNEP initiative
http://nuclearinfo.net
Nuclear Proliferation
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A single large Nuclear Power plant
produces large amounts of 239Pu. More than
enough for 100’s of nuclear weapons.
However over time they also produce a
significant amount of 240Pu.
Too much 240Pu makes it very difficult to
construct a Nuclear Weapon.
Weapons Grade Plutonium is defined to
have less than 7% 240Pu.
http://nuclearinfo.net
Nuclear Proliferation
After 4 months operation in a Light Water reactor the 240Pu
concentration exceeds 7%
Operating a Commercial Light water reactor under the IAEA
Additional Protocol is a low proliferation risk activity
http://nuclearinfo.net
East Australian Electricity demand
http://nuclearinfo.net
Alternatives - Renewables
The Earth receives vast amounts of solar energy. In
principle more than enough for an advanced civilizations
energy requirements.
Energy from the sun can be harnessed through:
 Hydro-Electricity
 Biomass (Burning organic products.)
 Wind
 Solar Thermal including passive heating
 Solar PhotoVoltaic’s
All these can and are making a significant contribution to our
energy needs
Plus GeoThermal (uses Earth’s Radioactive resources)
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http://nuclearinfo.net
Renewables
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However it’s not clear that these can meet all our
energy needs.
Hydro is basically exhausted in Australia and
faces environmental concern elsewhere
Biomass cannot supply both food and fuel in
many parts of the world. (Current energy use is
10% of total global photosynthesis)
Wind is not suitable for large scale base-load
generation. (Plus is more expensive.)
Solar-electric is also not suitable for Base-Load
generation. (Plus is also more expensive.)
Limited availability for GeoThermal
http://nuclearinfo.net
Wind Variability
CSIRO study
assuming 3 GW
of generating
capacity spread
over SA, Vic
and NSW.
Best sites give
30% utilization
http://nuclearinfo.net
Wind energy density
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Average output is at best 1.3 MW/ km^2
No trees
allowed over a
wind farm
Extra costs
involved in
handling
varying supply
http://nuclearinfo.net
Clean Coal
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Idea is to capture CO2 emissions and store them
deep underground.
World capacity is sufficient for 80 years of current
CO2 production.
Challenge: Each year a 1 GW Coal plant produces
around 6 million tonnes of CO2 gas.
The Bass Straight structures have the potential for
2 – 6 Billion tonnes of CO2 storage.
Sufficient for 55 – 150 years output at current rate
Incremental cost increase expected 2- 4 cents/KWHr
http://nuclearinfo.net
New nuclear technology
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Variety of new reactor designs that are at least 50
times more efficient and can destroy the TransUranic waste. (4th Generation)
Waste is reduced to 1 tonne per year. Isolation
time of 500 years.
Hydrogen gas can be cheaply generated via
thermo-chemical reactions using the High
Temperature reactors.
This can be used in place of Petroleum for many
transport needs.
Projected cost equivalent to 40 cents/litre petrol.
http://nuclearinfo.net
Advanced (Fast) Reactors
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Use unmoderated (or lightly) neutrons.
Avoids neutron losses plus can directly
fission 238U and other even actinides
Can “burn” long lived radioactive waste
http://nuclearinfo.net
“Fourth Generation” reactors
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The Gas-Cooled Fast Reactor (GFR)
Very-High-Temperature Reactor (VHTR)
Supercritical-Water-Cooled Reactor
(SCWR)
Sodium-Cooled Fast Reactor (SFR)
Lead-Cooled Fast Reactor (LFR)
Molten Salt Reactor (MSR)
http://nuclearinfo.net
Goals of the “4th Generation”
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They efficiently utilize Uranium
Destroy a large fraction of nuclear waste from current reactors via
transmutation.
Generate Hydrogen for transportation and other non-electric energy
needs.
Be inherently safe and easy to operate.
Provide inherent resistance to Nuclear Weapons proliferation.
Provide a clear cost advantage over other forms of energy generation.
Carry a financial risk no greater than other forms of energy
generation.
Not before 2020 at the earliest
If successful will provide energy indefinitely
http://nuclearinfo.net
Accelerator Driven Systems
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Use a very high powered accelerator to
provide neutrons to a subcritical assembly
No possibility of a melt-down.
Provides an energy gain and
Destroys long lived isotopes through
transmutation.
Requires around 50 MW of proton beam
(current best around 2 MW)
http://nuclearinfo.net
Australian Context
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Australia has the largest CO2 emissions per
capita in the OECD (27 tonnes Per Person)
Finland has CO2 output of 8.6 tonnes/person
Australian Per Capita energy consumption is
approximately the same. Electricity
consumption in Finland is 60% more.
Finland (and Sweden and France) is where
Australia should be by 2050.
Finland continues to invest in Nuclear Power
http://nuclearinfo.net
Planning Issues
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Australia is a democratic and open society
with many opportunities for citizens to
influence local developments.
Top down and imposed decisions can face
fierce opposition (cf some Wind Power.)
Any development of large scale facilities
must provide net benefits to locals
Time scales of the order of many years are
typical.
http://nuclearinfo.net
Regulatory Issues for nuclear
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Overseas (particularly US) experience
shows the importance of correct regulatory
framework.
Australia does not have this.
Need to achieve economies of scale for
light water reactors
Operating a reactor requires significant
expertise. Need to establish and monitor
World Best Practice
http://nuclearinfo.net
My opinion.
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Credible case for Nuclear Power
Nuclear Power can displace the huge Fossil
Fuel base-load electricity requirements.
But Nuclear Industry needs to demonstrate
Advanced Passive reactors work and are the
prices advertised.
Carbon Dioxide sequestration also has
potential but is less mature
For Australia, going the Nuclear route would require
a significant consensus that this is the best way
forward on the part of Society.
http://nuclearinfo.net
Recommendations
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We should take advantage of economies of scale and deploy a significant
number of reactors (more than say, six 1 GW reactors) so that the costs of
waste disposal and fuel enrichment can be shared.
Local communities should be encouraged to bid for nuclear investment.
Decisions should not be imposed.
An Australian Nuclear Industry must be pro-active in engaging with the
World Community and employ World Best Practice levels of Safety and
operations.
We would need an independent and pro-active regulatory framework to
oversee the operations of a Nuclear Industry.
The activities of the Regulators and the Industry must be open to the public
and all decisions should be fully transparent.
We must invest in research to find and build a suitable site for geologic
disposal of waste.
We must decide on appropriate means of transporting the waste to the site.
http://nuclearinfo.net